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(No Model.) 6 sheets sheet 1.

P. WRIGHT. TRANSFORMER SYSTEM OF ELECTRICAL DISTRIBUTION. No. 521,925.Patented June 26, 1894.

Jil y THE NATIONAL umoemmma COMPANY.

' WASHINGTON u. c.

(N0 ModeL) 6 Sheets-Sheet 2.

P. WRIGHT. TRANSFORMER SYSTEM OF ELBGTRIOAL DISTRIBUTIUN. No. 521,925.Patented June 26,1894.

Vii/mam: [72205722011 I @WM/ ffer (No Model.) 6 SheetsSheet 3.

P. WRIGHT. V TRANSFORMER SYSTEM OF ELECTRICAL DISTRIBUTION.

Patented June 26,1894.

[72/ 7/672 Z0 7-. l afer Wig/bi THE NATIONAL LDYMOGHAPHINE COMPANY.

(No Model.) 6 SheetsSheet 4.

P. WRIGHT.

TRANSFORMER SYSTEM OF ELECTRICAL DISTRIBUTION.

N0. 521,925. Patented June 26,1894.

Whzwmw: Zrzaemiar: a flwwa/u/ j eierfl r'lg7&i g/ jy p m as mk zfak (-NoModel.) 6 Sheets-Sheet 5.

I P. WRIGHT. TRANSFORMER SYSTEM OF ELECTRICAL DISTRIBUTION.

No. 521,925. Patented June 26,1894.

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- F15 SN RS- I ms NATIONAL umoennwmua company UNITED STATES PATENTOrrrcn.

PETER VVRIGl-IT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE UNITEDGAS IMPROVEMENT COMPANY, OF SAME PLACE.

TRANSFORMER SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent N0. 521,925, dated June 26,1894,

Application filed January 3, 1894.. Serial No. 495,519. (No model.)

To aZZ whom it may concern.-

Be it known that 1, PETER WRIGHT, a citizen of the United States,residing at the city of Philadelphia, in the county of Philadelphia andState of Pennsylvania, have invented certain new and useful Improvementsin Transformer Systems of Electrical Distribution, of which thefollowing is a specification.

Hitherto it has been customary to employ a transformer of sufficientcapacity for supplying the maximum requirements of the secondarycircuit; however in practice, for example, in electric lighting, itfrequently happens that the maximum requirements of the secondarycircuit are reached for a comparatively small portion of the time.During the remainder of the time, i. e. when the secondary circuit isnot working at its maximum capacity, there exists a considerable loss orwaste in the primary circuit due to the fact that the capacity of thetransformer is too great in proportion to the work being done by thesecondary circuit.

The principal objects of my present invention are, first, to obviate theabove mentioned waste and to provide several transformers that areautomatically called upon to energize the secondary circuit or areautomatically cut out therefrom according as the latter is called uponto do more or less work; second, to construct and arrange these severaltransformers in such manner that they are automatically cutinto or outof action by the increase or decrease of current due to an increase ordecrease of work required of the secondary circuit, and third, toprevent short circuiting the secondary circuit of one transformerthrough the secondary circuit or secondary coils of the other, byclosing the primary circuit of all additional transformers beforeclosing their secondary circuits and by opening their secondary circuitsbefore opening their primary circuits, whereby the liability of theoccurrence of a destructive spark is reduced because there is always aclosed circuit through one transformer.

My invention consists of the improvements hereinafter described andparticularly referred to in the claims.

The nature, characteristic features, and scope of my invention will bemore fully understood from the following description taken in connectionwith the accompanying draw ings forming part hereof and in which Figure1, is an end elevation showing portions of a switch adapted to respondto changes in the secondary current and to cut the primary and secondarycoils of one of the transformers into and out of circuit. Fig. 2, is afront elevational view of portions of the same. Fig. 3, is a rearelevational view of the same, showing the spring contacts and conductingbridge pieces and insulating cylinder, whereby the primary and secondarycoils are cut out of and into action. Fig. 4., is a sectional view takenon the line a4 of Fig. 1. Fig. 5, is a diagrammaticillustration showinga switch, spring driven gearing, and thermostat of Figs. 1 to 4, inapplication to circuits arranged according to my invention. Fig. 6, is asimilar view of a modification of my invention in which use is made of alocal circuit electro magnet and circuit breaker controlled by thethermostat and adapted to.

permit of the starting and stopping ofa train of gears operated byweight and in which use is also made of mercury contact snap switchesfor the transformer circuits. Fig. 7, is a view of a train of gearsoperated by weight and adapted to drive the shaft illustrated in Fig. 6.Fig. 8, is an end elevational view of the circuit breakerillustrated inFig. 6. Fig. 9, is an elevational view of the snap switches and certainof their accessories, shown in Fig. 6. Fig. 10, is a diagrammatic viewillustrating an arrangement embodying features of my invention and inwhich use is made of an electric motor and condenser operated from theline current and adapted to actuate the transformer switches. Fig. 11,is an elevational view of a portion of the intermediate drivingmechanism shown in Fig. 10. Fig. 12, is an elevational view of thecircuit breaker illustrated in Fig. 10. Fig. 13, is a sectional view ofthe circuit breaker shown in Fig. 12. Fig. 14., is a section taken onthe line 14:'14, of Fig. 10. Fig. 15, is a diagrammatic Viewillustrating my invention and showing a motor operated by the secondarycircuit of the transformer. Figs. 16 to 18, are views illustrating theautomatic circuit breaker shown in Fig. 15, and Figslt) and 20, areviews illustrating the employment of a motor operated by electromagnets.

In the drawings, a and a, (Figs. 5, 6, 10, and 15) are the conductors ofa line circuit, which, in practice, is usually located in a streetor'highway.

b and Z), are transformers of which Z), is assumed to be of the capacityrequired for lighting a certain number of lamps for example, the lampscc and 0c, and of which I) and 1), taken together are assumed to be ofthe capacity required for lighting the lamps a: and w, and also thelamps 00 ,00 and :0 or in other words, doing the maximum of work. Theprimary coil 1 of the transformer 12, is included in the line circuit aa, by means of conductors b and b, and the primary coil 6 of thetransformer b, is included in or excluded from the line circuit a 0.,according as its conductors Z2 and b are electrically connected or areinsulated from each other.

One of the respective ends of each of the secondary coils b and 12, ofthe transformers b and b, are connected with the secondary or lampcircuit 6 e, by means of conductors b and b. The other end of the coil 5is connected with the secondary circuit 6 e, by means of a conductor Z9and the other end of the coil I), is connected with or disconnected fromthe secondary or lamp circuit 6 e, according as the two parts of theconductor I), are in electrical connection with or are insulated fromeach other.

It may be remarked that the two portions of the primary circuit 1) and19 should be connected before the two portions Z1 of the secondarycircuit are connected together in order to avoid shunting or shortcircuiting the secondary circuit of the transformer 12, through thesecondary coil Z), of the transformer Z), and it may also be remarkedthat the two portions I), of the secondary circuit should be opened ordisconnected before the two portions of the primary circuit b and 12 areopened or disconnected. It will be obvious that this arrangement reducesthe liability of the occurrence of a destructive spark because there isalways a closed circuit through one trans former. Of course varioustypes of switches for example, mercury or snap switches, Figs. 6 and 9,may be employed for this purpose. However, in Figs. 3, 5, 10, 14, and 15of the drawings, I have illustrated a revoluble insulating cylinder cl,provided upon its curved surface with conducting bridge pieces a and 0,adapted to contact with brushes or other terminals applied to the endsof the respective parts of the conductors of the primary and secondarycircuits of the transformer 11'. The bridge piece 0, is Wider than thebridge piece a, and in such manner that the bridge piece 0, closes itscorresponding primary circuit before the bridge piece 0', closes itscorresponding secondary circuit, and the bridge piece 0', opens itscorresponding secondary circuit before the bridge piece 0, opens itscorresponding primary circuit. This switch for controlling the'circuitsb b and 19 may, of course, be operated or shifted through theintervention of various types of mechanism, for example, through theintervention of a small motor, Figs. 10 and 15, or weight, Figs. 6 and7.

As illustrated in Figs. 1 to 5, use is made of the following mechanismwhich may be inclosed in a suitable housing or case, not shown, forrotating the cylinder d. f, f',f ,f f, f and f are a train ofintermeshing gears or spur wheels revolubly supported between plates g,and actuated by means of a spiral spring 8, that may be Wound up throughthe intervention of pawl-and-ratchet connections 8, by means of asuitable key, or that may be made self-winding by means of suitable wellunderstood electro magnetic devices. If preferred, any other primemover, such as a weight or motor may be employed for driving a train ofgearing. Instances of such construction are hereinafter described andare illustrated in Sheets 3, 4, and 5, of the accompanying drawings. h,is a pinion keyed to the shaft cl, of theinsulating cylinder d, andmeshing with the spur wheel f so that when the train of gears is inmotion, the insulating cylinder iscaused to revolve in a clockwisedirection, thus making and breaking the primary and secondary circuitsof the transformers b and Z). t', is a revoluble spindle mounted in theplates g, in such manner that its respective extremities project beyondthe same as Shown in Figs. 2 and 4, and in such manner that it isallowed a range of play in the direction of its length. This spindle i,is provided with a tight or keyed lanternwheel 2', meshing with thespur-wheel f, in all positions of the spindle 1'. Upon the spindle t',is mounted a sleeve t afforded a range of endwise play but constrainedto rotate with the spindle. This sleeve 7?, is provided with radial arms2' and is normally solicited by means of a spring t, against a collar '5fast on the spindle. j, is a shipperrod afforded a range of endwisemovement and provided with arms or projections 7' adapted to contactwith the ends of the spindle k, is a sliding bar provided with fingersor stop pins adapted to be brought into engagement with the radial armsi in order to check the movements of the gearsfifflfi f ,f ,f and f Fromthe foregoing description, it will be obvious that the fingers or stoppins 70, may be caused to engage the radial arms i either by shiftingthe sliding bar, 75, or by shifting the spindle t'. The former result isaccomplished by means of acam-faced wheel 61?, mounted fast upon theshaft (1, and running between the forked or bifurcated end of acentrally pivoted lever Z, the other end of which is provided with anopening through which passes the threaded end of the sliding bar 70. W,are nuts for permitting of the adjustment of the throw of the slidingbar 70, in order to insure the proper timing of the operations of thedevice. The required movements of the shipper-rod j, are effected bymeans of a device m, responding to changes in the current of thesecondary or lamp circuit e e. In the present instance the device m,comprises a thermostat secured at one end to an insulating binding postcarried by the base 9', and connected at its other end with theshipper-rodj, through the intervention of a rod m, having a section ofinsulating material m interposed therein.

WVhile I have shown in the accompanying drawings an exceedingly simpleform of thermostat, still I wish it to be distinctly understood that Ido not limit myself to such form of thermostat, as many known types ofso-called compensating thermostats may be employed.

m are nuts for adjusting the throw of the shipper-rod j, in order toinsure the proper operations of the device. It may be remarked that thespring 2'", by yielding prevents injury of the fingers 7c, and radialarms The thermostat shown in the drawings comprises two sheets ofmaterial whereof one is of greater electrical conductivity than theother, and its free end is shifted toward the right in Fig. 2, when thecurrent traversing it is considerable and corresponds to that whichwould be beyond the capacity of the trans-- former b, that is to whatwould be required to light all the lamps, and toward the left in saidfigure when the current traversing it is less and corresponds to thatrequired by the lesser number of lamps, in the present instance thelamps :r 03.

The mode of operation of my improved transformer system of electricaldistribution, as illustratedin Figs. 1 to 5, maybe described as follows:Then the primary circuit 6 e','is required to do a comparatively smallamount of work, for example, to light the lamps 03:0, the transformer h,supplies all the current and the primary and secondary circuits of thetransformer Z), are both interrupted by means of the switch cl. Assumingthat the lamp circuit 6 e, is called upon to do more work andconsequently to carry more current, for example, by the lighting of thelamps 00 m and 50 in addition to the lamps on and 03', it follows thatan increase of current traverses the device m. This device m, respondsto the increase of current and its free end is deflected thereby, towardthe right in Fig. 2. This movement of the free end of the device an,causes the shipper rod j, and with it the armsj to be shifted and toshift the spindle 2', toward the right, whereby the arm i is moved clearof the stop pin or finger thus permitting of the movement of the trainof gearsf, f',f f t), f, and f and consequent rotation of the shaft (1.The revolution of the shaft cl, causes the cylinder d, to be rotated ina clockwise direction with the result that the primary circuit of thetrans former h, is first closed by the conducting bridge piece 0, andthe secondary circuit of the transformer b, is subsequently closed bythe bridge piece 0, thus bringing the transformer 1), into action andinsuring the requisite supply of current to the lamp circuit e e, asshown in Fig. 5. As soon as the primary and secondary circuits of thetransformer b, have been closed, the continued rotation of the shaft cl,and cam-wheel 01 causes the latter to shift the sliding bar 7c, towardthe left in Fig. 2, with the result that the end of its left hand fingeror stop pin is, engages the radial arm i thus checking the movement ofthe train of gears and parts actuated thereby. Should the quantity ofcurrent required by the lamp circuit e e, be diminished, for example, bythe extinguishment of the lamps 00 m and 00 then the current traversingthe device m, will also be diminished whereby the free end of thisdevice will be returned automatically toward the left in Fig. 2, to itsoriginal position. This movement of the free end of the device m, causesthe spindle z, to be shifted toward the left, so that its radial arm iis clear of the right hand stop pin or finger it, whereupon the train ofgears is again permitted to move and to revolve the shaft d. Thisfurther revolution of the shaft d causes the primary and secondarycircuits of the transformer 19, to be interrupted bythe insulatingportions of the cylinder d, whereby the transformer b', is automaticallycut out of action. This revolution of the shaft (1, also causes thecam-wheel 01 to shift the left-hand stop pin or finger 7c, intoengagement with one of the radial arms 1, whereby the train of gears isbrought to rest, thus permitting the transformer b, to remain out ofaction until the current traversing the device m, again increases andconsequently operates to cut the transformer 12, again into action inthe manner above set forth.

Referring now to Figs. 6 to 9 inclusive,

which embody my invention and illustrate the use of snap switches,propelling weight, and a local battery circuit and its accessories, n,is a local battery orother source of electric energy. One conductor 72,of this battery traverses the coils of electro magnets a and proceedsthence to the centrally pivoted and insulated tongue n thence by thecontacts and conductors n or 92 (according to the position of thetongue) to the back stops at and m and thence by a conducting plate acarried by and insulated fromthe thermostat m, and by the conductor a",to the battery n. The electro magnet n is provided with a centrallypivoted armature lever 0, having two arms or fingers o and 0 whereof thefinger o, is normally solicited by a spring 0 into range of arms 0,projecting from a spindle driven through the intervention of a train ofgearing o, 0 and 0 and whereof the other finger o rides upon a cam-wheel0 also driven by the gearing. o, is a weight for im parting motion tothe gearing. 0 and o are snap switches provided with mercury cups 0 Fig.9, and with centrally disposed con-' tacts 0 These snap switches areoperated by means of cams 0, mounted on the shaft cl, which latter ispositively driven by means of the train of gears. 0 is a cam-wheelmounted upon the shaft cl, and adapted to run between the forked end ofthe tongue a and thus shift the latter in such manner that its other endis caused to rest alternately upon the contacts or terminals of theconductors n and M. For the sake of a further description, it will beassumed that all the lamps w, 00, 03 ,50 ,00 are being supplied withcurrent from both the transformers b and b. When the lamps x x and 03are extinguished, the current traversing the thermostat m, will bediminish.ed,whereuponthefree end of the thermostat is shifted toward theleft, so that the conducting plate a is brought into contact with theback stop it. Under these circumstances, the local battery circuittraverses the conductor n, coils of electro magnet 07?, tongue nconductor a back stop a, plate a and conductor a". This current causesthe armature 12 to be attracted, thus shifting the finger 0', clear ofthe arms 0 and also raising the finger 0 out of the low part of the cam0 The train of gears being thus released is rotated under theinfluenceof the weight 0 and causes revolution of the shaft d and camwheel 0 Therevolution of the shaft 61, is productive of the following results:First, it causes the cams o to lift the snap switches 0 and 0 to breakthe primary and secondary circuits of the transformer 12, in the mannerabove described, that is to break the secondary before the primary;second, it causes the cam-wheel 0 to transfer the tongue n from thecontact of the conductor n thus breaking the local circuit of theconductor a and, third, it causes the finger 0 to ride upon the highpart of the cam 0 until the completion of the foregoing operations,where upon the finger o falls into a low part of the cam 0 thuspermitting the finger 0, moving under the influence of the spring 0 toengage the arms 0 and thus arrest the mechanism. For the sake of afurther description, it will be assumed that the lamps 00 m and x areagain turned on. Under these circumstances, the increase of currenttraversing the thermostat m, causes the plate 71 to be brought intocontact with the back stop 02 thus completing thelocal circuit andpermitting the mechanism to rotate and subsequently arrest the shaft d,in the manner above described but in such position that the snapswitches o and 0, close their respective circuits. In this connection,it may be remarked that the particular type of circuit breaker a abovedescribed, is not essential, as other forms of circuit breakers, forexample, those shown on Sheets 4 and 5 of the drawings and hereinafterdescribed, may be employed.

In Figs. '10 to 14, use is made of an electric motor A, and of acondenser B, in parallel with the line circuit a a, by means ofconductors p and 13'. Of course the condenser B, may be in series in theline a a. The motor A, drives the shaft 01', through the intervention ofsuitable differential gearing, for example, that shown in Fig. 11. Inthis instance, the shaft 61, is provided with an insulating cylinder 61,hereinbefore described in connection with Figs. 1 to 5, however, ifpreferred, use might be made of snap switches, such for example as areillustrated in Figs. 6 and 9. The shaft d, is also provided with anautomatic circuit breaker, and, in the presentinstance, this circuitbreaker comprises an insulated disk 01 having upon its face overlappingconducting segments 19 and p, of different radii, Fig. 12, and having ahub 13 Fig. 13, in electrical connection with each of said segments, andit also comprises spring contacts 19 p and p cooperating with said huband conducting segments.

The mode of operation of the apparatus illustrated in Figs. 10 to 14,may be described as follows: When the free end of the thermostat isdeflected toward the left, for example, by the extinguishment of thelamps 1: 50 and at, current is supplied to the motor by the conductor pplate a back stop it, conductor 19 spring 19 segment p hub 19 spring 19and conductors 13 and 19. Under these circumstances, the motor is set inmotion and drives the shaft 61', through the intervention of the gearingillustrated in Fig. 11, thus causing the switch d, to break therespective circuits of the transformer I), thus cutting it out ofaction, the rotation of the shaft (1, also causes the disk 19 to turn inthe direction indicated by the arrow, Fig. 12, thus permitting thecontacting spring 19 to ride onto a portion of the disk and thus breakthe circuit through the motor, whereby the same comes to rest. If thefree end of the thermostat m, should now be deflected toward the right,for example, by the lighting of the lamps x x and x current would besupplied to the motor A, through the condenser B, by the conductor pplate a back stop n conductor 19 spring 1), segment 19, hub 17, andconductors 19 and p to the condenser. Under these circumstances, themotor A, would again drive the shaft 01, and cause the cylinder d, tocomplete the circuits of the transformer b, and subsequently cause thecircuit breaker to again arrest the motor by interrupting its circuit.

Referring now to Fig. 15, the condenser or local battery is dispensedwith and the motor is driven by current derived from the secondarycircuits. The motor in its turn drives the shaft at, through theintervention of suitable differential gearing, such, for instance, as isillustrated in Fig. 11. In this figure I have shown a slightly differentform of circuit breaker, however, the forms of circuit breakerhereinbefore described, may, if preferred, be used. The circuit breakerillustrated in Fig. 15, comprises three disks q, q and Q2, mounted sideby side, Figs. 16 to 18 inclusive and insulated from each other by theinterposition of suitable material. The disks q and q, are providedrespectively with IIO conducting segments g and g disposed opposite eachother, and the disk 1 is composed wholly of conducting material and isin electrical connection with each of the conducting segments g and gThis circuit is, of course, provided with contact springs q and g Nhenthe free end of the thermostat is deflected toward the left, for exampleby the extinguishmentof the lamps x 00 and :0 current is supplied to themotor from the lamp circuit e e, or in other words, from the primarycircuit of the transformers b b, by a conductor (1 a conductor g contactspring (1 disk transverse rods q conducting segment g, of disk q,contact spring 1 cond uctor q, back stop a, plate a conductor Q12, tothe other conductor or side of the lamp circuit. Under thesecircumstances, the motor A, causes revolution of the shaft d, thusserving to interrupt the primary and secondary circuits of thetransformer 19, either by means of the insulating cylinder (Z, as shown,or by means of snap switches as has been hereinbefore explained. Therotation of the shaft cl, subsequently causes the contact spring 1 toride upon the insulating portion of the disk q, whereupon the localcircuit is broken and the motor consequently permitted to cometo rest.When the free end of the thermostat m, is deflected toward the right,for instance by the inclusion of the lamps x 00 and :0 current issupplied to the motor A, from the lamp circuit by the conductors g andq, contact spring (1 disk g rods insulated portion g disk-g, springcontact o conductor (113, back stop at, plate a and conductor (1 Underthese circumstances the motor A, again rotates the shaft cl, thuscausing the closing of the primary and secondary circuits of thetransformer 19', and subsequently causing the circuit breaker tointerrupt the local circuit at the disk q, whereby the motor ispermitted to again come to rest.

In Figs. 19 and 20, use is made of a crosshead 7", transversely slottedas at 'r, for the accommodation of a crank-pin W, by means of which theshaft d, and cylinder d, are rotated. This cross-head r, is providedupon its opposite sides with cores r that constitute parts of thesolenoids r and r r, are springs that press with their free extremitiesupon a disk or wheel rlkeyed to the shaft d, and provided withperipheral notches r into which the ends of the springs r, are adaptedto take and thus prevent the disk or wheel 1, from coming to rest withthe crank pin W, in line with the cores W, or in other words upon a deadcenter. The disposition of the line, lamp, primary and secondarytransformer circuits are the same in Figs. 19 and 20, as in certain ofthe preceding figures and consequently corresponding parts thereof aredesignated by the same reference letters and further description isunnecessary. When the free end of the thermostatic device m, isdeflected downward, for example by reason of the extinguishment of aportion 93 0c ,ac and m of the lamps, a circuit derived from one side ofthe lamp circuit is closed through the conductor t, conducting plate aback stop a, conductor 25, coils of solenoid r conductors t and t andback to the other side of the lamp circuit, as illustrated in Fig. 19,by way of the conductor 19 Under these circumstances, the solenoid rdraws its core into its coils as shown in Fig. 20, thus causing thecross-head and crank pin T to turn the cylinder d, into position forinterrupting the primary and secondary circuits of the transformer b, inthe manner above described, whereby this transformer is cut out ofaction. In this connection it may be remarked, that the springs r, andperipherally notched wheel 0*, prevent the stoppage of the crank pinupon a dead center. When the free end of the thermostatic device m, isdeflected upward (Fig. 19) for example, by reason of the lighting of thelamps 00 m 0: and 03 the circuit derived as before from the side e, ofthe lamp circuit by way of the conductor 25, and conducting plate a iscompleted through the back stop of, conductor 25, and coils ofthesolenoid r, and thence as before through the conductors 15 t and Z9 tothe other side e, of the lamp circuit. Under these circumstances thesolenoid shifts the cross head toward the left in Fig. 20, thus causingthe cylinder d, to be turned back into position for again closing theprimary and secondary circuits of the transformer 12, whereby the latteris automatically brought into action.

It will be obvious to those skilled in the art to which my inventionappertains that modifications may be made in details without departingfrom the spirit thereof, hence I do not limit myself to the preciseconstruction and arrangement of parts hereinabove set forth, but

Having thus described the nature and ob jects of my present invention,what I claim as new, and desire to secure by Letters Patent,

is- I 1. A transformer system of electrical distribution comprising,several transformers, and a switch responding to changes in current andadapted to automatically interrupt the secondary circuit beforeinterrupting the primary circuit and to close the primary circuit beforeclosing the secondary circuit of one of the transformers, substantiallyas described.

2. A transformer system of electrical distribution comprising, severaltransformers, and a switch responding to changes in current in thesecondary circuit and adapted to automatically interrupt the secondarycircuit before interrupting the primary circuit and to close the primarycircuit before closing the secondary circuit of one of the transformers,substantially as described.

3. A transformer system of electrical distribution comprising, twotransformers having independently energized primary coils and havingtheir secondary coils adapted for IIO IZC

inclusion in and exclusion from the same secondary circuit, and a switchresponding to changes in the current of the secondary circuit andadapted to automatically close the primary circuit of one of thetransformers before closing its secondary circuit and to open thesecondary circuit before opening the primary circuit of the lastmentioned transformer, substantially as described.

4. A transformer system of electrical distribution comprising,asecondary circuit, two or more transformers for supplying current tosaid circuit, and a switch responding to changes in the current of saidcircuit and operating to automatically open the secondary.

circuit and to subsequently cut out one or more of said transformers andto cut one or more of said transformers into action before closing itsor their secondary circuit or circuits, substantially as described.

5. In a transformer system of electrical distribution, a switch tendingto make and break the primary and secondary circuits of a transformer,and a thermostatic device responding v to changes in current and adaptedto release said switch, substantially as described.

6. In a transformer system of electrical distribution, a switch tendingto make and break the primary and secondary circuits of a transformer, athermostatic device responding to changes in current and adapted torelease said switch, and a positively driven cam-wheel and its slidingbar and stop fingers for automatically arresting said switch,substantially as described.

7. In a transformer system of electrical distribution, a switch operatedby positively driven gearing adapted to rotate an endwise movablespindle having radial arms, a shipper rod having arms disposed in rangeof the ends of said spindle, a sliding bar having stop fingers or pinsadapted to contact with said radial arms, and a thermostat and camwheelfor operating said sliding and shipper bars, substantially as described.

8. In a transformer system of electrical distribution,a transformer, anda device responding to changes of current and adapted to successivelyinclude and to successively exclude the primary and secondary coils ofsaid transformer, whereby sparking and disruptive discharges areprevented, substantially as described.

9. In atransformer system of electrical distribution, a transformer, arevoluble shaft, means for actuating said shaft, a thermostatic devicefor controlling said shaft, and devices operated by said shaft andadapted to cut the said transformer into and out of action,substantially as described.

In testimony whereof I have hereunto signed my name in the presence ofWitnesses.

PETER ,IVRIGIIT. Witnesses:

A. B. STOUGHTON, K. M. GILLIGAN.

